INTRODUCTION OF LABORATORY

The remarkable discovery of high-Tc superconductivity and the following enthusiastic research in the last decades have clearly demonstrated how the finding of new materials would give a great impact on the progress of materials research and solid state physics. Now related topics are spreading over not only superconductivity but also unusual metallic behavior that is generally observed near the metal-insulator transition in the strongly correlated electron systems. We believe that for the next few decades it will become more important to explore novel physics through searching for new materials. Transition-metal oxides are one of the most typical systems where the effect of Coulomb interactions plays a critical role on their magnetic and electronic properties. Especially interesting is what is expected when electrons localized due to the strong Coulomb repulsion start moving by changing the bandwidth or the number of carriers. We anticipate there an unknown, dramatic phenomenon governed by quantum fluctuations. Topics we are now studying are superconductivity hopefully with higher Tc values and quantum spin systems with the triangle geometry where a magnetic frustration may lead to an unusual spin liquid ground state. One of our recent progresses is that we found superconductivity for the first time in the pyrochlore oxides α-Cd2Re2O7 and β-AOs2O6 (A = K, Rb, Cs), as shown in the above figure.

当研究室で発見された新超伝導体